Wednesday 27 June 2012 01.00 EDT
First published on Wednesday 27 June 2012 01.00 EDT

A two-and-a-half year legal battle over a "joke" posted on Twitter that landed its author with a criminal record returns to the high court on Wednesday in front of the most senior judge in England and Wales.

Paul Chambers, an unemployed former trainee accountant, is appealing against his conviction for tweeting that he would blow up Doncaster's Robin Hood airport unless it reopened so he could fly to see his new girlfriend.

The case will be heard in front of the lord chief justice, Lord Judge, Mr Justice Owen and Mr Justice Griffith Williams. It brings the number of judges and magistrates who have considered Chambers' case up to nine, spread over seven days in court since his tweet on 6 January 2010.

During snowy weather, Doncaster's Robin Hood airport had closed, threatening to derail Chambers' plans to fly to Belfast to meet Sarah Tonner, a woman he had met on Twitter. He tweeted on the publicly accessible feed: "Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!!"

Chambers was convicted and fined £1,000 on a charge of "sending a public electronic message that was grossly offensive or of an indecent, obscene or menacing character contrary to the Communications Act 2003".

Chambers has argued through his barristers that the tweet was facetious and a parody and that the conviction was "a steamroller to crack a nut". He will be represented by crime and civil liberties barrister John Cooper QC and Sarah Przybylska.

Article 19, an international campaigning group for freedom of expression, has made a submission to the high court asserting that to criminalise a statement that was not intended as a threat and that an ordinary reasonable person would understand to be a joke would amount to a disproportionate interference with the European convention on human rights and the international covenant on civil and political rights, a treaty adopted by the United Nations general assembly.

Article 19 said the context of statements made on the internet must include the "fervent, if not florid" nature of its discourse, its tendency towards "rapid and spontaneous exchange of comments" and its "broad range of tolerance for hyperbolic language". It said case law in Australia, Canada and the United States made clear the need to distinguish between mock and actual threats.

In previous hearings, the complexities of Twitter, the microblogging site launched in 2006, have been pitted against communications laws last updated in 2003. Lawyers and judges have wrestled with Twitter's conventions and technological peculiarities such as different filters for private and public messaging.

Lawyers for the Crown Prosecution Service argued: "The message was posted at a time when the potential threat to airport security was high. It was capable of being read by members of the airport staff and members of the public as a threat to airport safety and public safety."

In dismissing his first appeal in September 2010, judge Jacqueline Davies said the message was "menacing in its content and obviously so. It could not be more clear. Any ordinary person reading this would see it in that way and be alarmed".

But Padraig Reidy, news editor at Index on Censorship, the free speech pressure group, said: "There has been an absolute failure to grasp what a tweet is and how people interact on social networking sites and the law that is being used is not fit for the age we live in. It could not possibly have anticipated the way we interact now."

The appeal is expected to last one day and judgement is likely to be handed down at a later date.